Intake Manifold; Description - Inlet Port Shut Off; Operation - Inlet Port Shut Off; Timing Chain Cover - Jeep 2002 WJ Service Manual

9a - 46 ENGINE
OIL COOLER & LINES (Continued)
(13) Start engine and inspect for leaks.
(14) Inspect engine oil level 2 minutes after turn-
ing engine off. Refill as necessary.

INTAKE MANIFOLD

DESCRIPTION - INLET PORT SHUT OFF

A swirl and a charge air inlet port each are pro-
vided in the intake manifold for each cylinder (Fig.
41). The charge air ports can be closed by means of
flaps. The flaps are connected to each other by link-
age, which is operated by the inlet port shut off
motor. The valves are held in position by means of
spring force.
Fig. 41 SENSOR LOCATION
1 - CRANKSHAFT POSITION SENSOR
2 - SWIRL ACTUATOR

OPERATION - INLET PORT SHUT OFF

With lower engine speed and load range, all charge
air ports are sealed off by way of flaps. The entire air
flow flows in only through the swirl inlet ports. This
results in a high air swirling which produces more
effective mixing of fuel with air, enhancing combus-
tion.
As engine speed and load rise, the charge inlet
ports are continuously opened to obtain the best pos-
sible ratio between air swirling and air mass for each
operating point. This
exhaust characteristics, and reduces soot.
The position of the flaps in the charge air ports is
determined by input received by the ECM (Engine
Control Module). The inlet port shut off motor
optimizes engine power,
receives a PWM signal from the ECM for this pur-
pose. A direct current motor pushes the adjusting
lever into the correct position. If a fault or an open
circuit occurs, the flaps are opened.

TIMING CHAIN COVER

REMOVAL

WARNING: DO NOT OPEN COOLING SYSTEM
UNLESS TEMPERATURE IS BELOW 90°c (194°F).
OPEN CAP SLOWLY TO RELEASE PRESSURE.
STORE COOLANT
ONLY. RISK OF INJURY TO SKIN AND EYES FROM
SCALDING COOLANT.
GLOVES, CLOTHING AND EYE WEAR.
(1) Disconnect negative battery cable.
(2) Drain coolant (Refer to 7 - COOLING/ENGINE/
COOLANT - STANDARD PROCEDURE).
(3) Drain engine oil.
(4) Remove engine cover (Refer to 9 - ENGINE -
REMOVAL).
NOTE: Inspect condition of hoses and clamps,
replace as necessary.
(5) Detach coolant hoses on thermostat housing.
(6) Remove air intake hose.
(7) Remove air charge pipe together with air
charge hose.
(8) Remove hydraulic cooling fan (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - REMOVAL).
(9) Remove viscous heater hose and set aside.
WARNING: NO FIRE, OPEN FLAMES OR SMOKING.
SERVICE VEHICLE IN WELL VENTILATED AREAS
AND AVOID IGNITION SOURCES. RISK OF POISON-
ING FROM INHALING AND SWALLOWING FUEL.
RISK OF INJURY FROM SKIN AND EYE CONTACT
WITH FUEL. POUR FUELS ONLY INTO SUITABLE
AND APPROPRIATELY
WEAR PROTECTIVE CLOTHING WHEN HANDLING
FUEL.
(10) Remove fuel high pressure lines and injectors
(Refer to 14 - FUEL SYSTEM/FUEL INJECTION/
FUEL INJECTOR - REMOVAL).
(11) Remove cylinder head cover (Refer to 9 -
ENGINE/CYLINDER
COVER(S) - REMOVAL).
NOTE: Rotate engine on crankshaft. DO NOT crank
the engine at the bolt of the camshaft sprocket.
NOTE: DO NOT crank engine back.
IN APPROVED CONTAINER
WEAR PROTECTIVE
MARKED CONTAINERS.
HEAD/CYLINDER
WG
HEAD